miR-146b negatively regulates the G₀/G₁ to S-phase cell-cycle transition by targeting Traf6. (A) BrdU vs 7AAD flow cytometric analysis of T cells stimulated with anti-CD3/CD28 antibodies and pulsed with 10 μM BrdU for 1 hour before harvest at the indicated time points. Plots are representative of duplicate samples. (B) Western blot analysis of Traf6 protein expression in purified CD4 T cells stimulated with anti-CD3/CD28 antibodies for the indicated times. (C) Western blot analysis of c-myc induction and p27 levels in purified CD4 T cells stimulated with anti-CD3/CD28 antibodies for the indicated times. Mice in (A-C) were littermate pairs between 6 and 8 weeks old on the C57BL/6 background (146a8/tPTEN^−/− in [B] was age matched). Data in (A-C) are representative of 2 independent experiments.